The present disclosure relates to an image forming apparatus including a shield case in which a circuit board mounted with an electric circuit is contained.
In an image forming apparatus, a control circuit board mounted with an electric circuit controlling various parameters with regard to image forming is contained in a shield case. The shield case is electrically connected, in general, to a main body frame at the back side of the image forming apparatus by screw fastening and grounded via the main body frame.
In a main body of the shield case, an aperture is bored, which is used for manipulating the control circuit board in a case of an inspection of the control circuit board, an extension of memory or other work. The aperture is configured to open/close by a lid member. If the lid member is not electrically connected to the main body of the shield case, an electromagnetic wave may be leaked from the shield case.
Therefore, in the shield case having the lid member fastened to the periphery of the aperture of the main body by a plurality of screws, protrusions may be formed between screw fastened parts in a back face of the lid member. When the lid member is fastened to the main body of the shield case by the screws, because the protrusions are pressed to the main body of the shield case by the lid member, the lid member and main body of the shield case are surely contacted and electrically conducted.
However, in the above-mentioned shield case, because the plurality of the screws must be used for fastening the lid member to the periphery of the aperture, there is a problem that labor and time are taken in opening/closing work of the lid member. Moreover, because a plurality of the protrusions are formed in the lid member, there is a problem that manufacturing cost of the lid member is increased.